Messaging systems and methods

ABSTRACT

Apparatus, methods, and machine-readable articles of manufacture improve reliability and scalability of a messaging system. In some embodiments, the system&#39;s configuration data and subscriber information are stored in a central repository of a core node, and replicated to one or more non-core nodes. Data replication may be performed in real-time or near real-time, periodically, sporadically, or otherwise. Nodes may rely on the replicated data to provide the system&#39;s subscribers and outside callers with services that do not involve updating of configuration or subscriber data. In this way, the non-core nodes may continue to process calls when the core node is unavailable. For example, the non-core nodes can route calls to the appropriate subscribers without relying on the core. As another example, the non-core nodes can take messages from callers when the core node is unavailable. The messages may be queued for posting and delivery when the core node becomes available.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 14/627,858, entitled MESSAGING SYSTEMS AND METHODS,filed 20 Feb. 2015, now allowed; which is a continuation of and claimspriority to U.S. patent application Ser. No. 11/747,154, entitledMESSAGING SYSTEMS AND METHODS, filed 10 May 2007, now U.S. Pat. No.9,001,691; which claims priority benefit of provisional U.S. PatentApplication Ser. No. 60/799,485, entitled SCALABLE UNIFIEDCOMMUNICATIONS SYSTEM, filed on May 10, 2006. Each of the foregoingpatent documents is incorporated by reference as if fully set forthherein, including Figures, Claims, Tables, and all other matter in thepatent documents.

FIELD OF THE INVENTION

The present invention relates generally to telecommunication systems andmethods, and, more particularly, to multi-node unified communicationssystems, including telephony systems such as telephone call managementauto attendant and voice messaging systems, and to electronic messagingsystems such as email, instant messaging (IM), and short message service(SMS) systems.

BACKGROUND

Telephone systems and telephone service providers offer a wide range ofvoice communication services, including call answering, voice messaging,and automated attendant services. With the trend towards combining voicecommunications with non-voice electronic communications (e.g., email,IM, SMS, facsimile), unified messaging systems have emerged. In unifiedmessaging systems, multiple types of communication services areavailable to a subscriber. For example, a subscriber's voice, facsimile,email, IM, SMS, and other messages may be stored on such a system andmade available to the subscriber upon request. The subscriber may beable to log into such system from a remote location, and receive (e.g.,view, listen to) voice and electronic messages, as well as sendelectronic messages and originate telephone calls from the system. Thesystem may also include groupware applications. (“Groupware” generallyrefers to applications that enable collaboration of a group ofsubscribers, such as employees of a company; groupware may provideservices for communication including email, contact management, andscheduling.) The system may also include additional capabilitiesintended to facilitate communications with the subscriber when thesubscriber is connected to the system remotely through a telephonenetwork. For example, the system may include a text-to-speech converterfor reading to the remotely-connected subscriber stored facsimile andemail messages.

The system may include multiple “nodes” in different geographiclocations, for example, in different areas of a building, differentbuildings, different cities, different states, or even differentcountries. Multiple nodes may also be physically located in the sameplace. The nodes are interconnected. Each of the nodes may be configuredto provide messaging services (e.g., receiving, creating, sendingmessages) to a particular subgroup of its associated subscribers andpossibly to other subscribers, for example, to the particular subgroupat the same geographical location as the physical location of the node.Configuration information and subscriber data are typically stored on acore node (as distinguished from other, non-core nodes). When the corenode is down, for example, because of maintenance and hardware orsoftware failures, normal processing of calls and other messages may bedisrupted.

Scaling the system up by increasing the number of nodes tends to slowdown message processing in the system, and particularly processing ofmessages within the core.

A need exists in the art to improve reliability of messaging systemswhen core nodes become unavailable, and to make such system morescalable.

SUMMARY

The present invention is directed to multi-node messaging systems,methods for operating multi-node messaging systems, and machine-readablearticles of manufacture storing code for operating multi-node messagingsystems that help satisfy this need. System configuration data and/orsubscriber data may be stored on the core node and replicated to thenon-core nodes, enabling the non-core nodes to provide certainfunctionality when the core node is inaccessible for some reason.

In an embodiment, the invention herein disclosed is a messaging systemthat includes a core node configured to provide central repositoryservices for storing system configuration and/or subscriber information,and one or more non-core nodes, each non-core node of the one or morenon-core nodes being in communication with (or including) telephoneswitching equipment (e.g., PBX). Each non-core node is configured toprovide a platform for running telephony and/or voice user interfaceapplications (TUI/VUI) for processing telephone calls. The core node andthe non-core nodes are configured to replicate at least a portion of thesystem configuration information and/or subscriber information stored onthe core node to the non-core nodes. In aspects of the invention, all ora plurality of the non-core nodes being in communication with a singletelephone switching equipment.

In an embodiment, the invention herein disclosed is a method ofoperating a multi-node messaging system that includes a core node andone or more non-core nodes. Each non-core node of the one or morenon-core nodes is in communication with (or includes) telephoneswitching equipment associated with the non-core node. The methodincludes storing system configuration information of the messagingsystem on the core node, replicating at least a portion of the systemconfiguration information stored on the core node to each non-core node,and running at each non-core node one or more telephony and/or voiceuser interface applications for processing telephone calls.

In an embodiment, the invention herein disclosed is a machine-readablestorage medium (e.g., a memory) with program code stored in the medium.When the program code is executed by at least one processor of amulti-node messaging system that includes a core node and one or morenon-core nodes, each non-core node of the one or more non-core nodesbeing in communication with (or including) telephone switchingequipment, the code configures the system to perform the followingsteps: (1) storing system configuration and/or subscriber information ofthe messaging system on the core node, (2) replicating at least aportion of the system configuration and/or subscriber information storedon the core node to each non-core node, and (3) running at each non-corenode one or more telephony and/or voice user interface applications forprocessing telephone calls.

In an embodiment, the invention herein disclosed is a messaging systemfor servicing a plurality of subscribers. The messaging system includesa primary core node configured to provide central repository servicesfor storing system configuration and subscriber information of themessaging system. The system also includes a plurality of non-corenodes, each non-core node of the plurality of non-core nodes beingconfigured to provide a platform for running telephony user interfaceapplications and voice user interface applications for processingtelephone calls. The system further includes a failover core nodeconfigured to provide the central repository services for storing systemconfiguration and subscriber information when the primary core node isunavailable, for example, due to failure. The primary core node and thefailover core node are configured to replicate the system configurationand subscriber information stored on the primary core node to thefailover core node. The failover core node is configured to take overcore node functions of the messaging system when the primary core nodein unavailable.

In an embodiment, the invention herein disclosed is a messaging systemfor servicing a plurality of subscribers. The system includes a corenode configured to provide central repository services for storingsystem configuration and subscriber information, a plurality of non-corenodes, and telephone switching equipment (for example, a single PBX) incommunication with each non-core node of the plurality of non-corenodes. Each non-core node is configured to provide a platform forrunning telephony user interface applications and voice user interfaceapplications for processing telephone calls of the plurality ofsubscribers. The core node and each non-core node are configured toreplicate at least a portion of the system configuration and subscriberinformation stored on the core node to each non-core node so that themessaging system can provide at least partial services to thesubscribers of the system and to outside callers when the core node isunavailable.

In an embodiment, the invention herein disclosed is a messaging systemthat includes a core node and one or a plurality of non-core nodes. Thecore node includes a core store configured to perform central repositoryservices for system configuration and subscriber information, and forstoring received and sent messages of subscribers of the system. Thecore store is an authoritative store of the system. The messages mayinclude telephone messages, email messages, facsimiles, instantmessages, short message service messages, and possibly other types ofmessages. Each non-core node of the plurality of non-core nodes isconfigured to provide a platform for running telephony, email,facsimile, IM, SMS and possibly other types of user interfaceapplications for processing the messages. Each non-core node includes acore store configured to store at least some of the messages. The corenode and the non-core nodes are configured to replicate at least aportion of the system configuration and subscriber information stored onthe core node to each of the non-core nodes.

These and other features and aspects of the present invention will bebetter understood with reference to the following description, drawings,and appended claims.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a high-level block diagram illustrating selected elements(hardware blocks, software process blocks, and/or combinedhardware-software blocks) of a node of an exemplary messaging systemconfigured in accordance with one or more aspects of the presentinvention;

FIG. 2 is a high-level block diagram illustrating selected elements of amessaging system configured in accordance with one or more aspects ofthe present invention;

FIG. 3A is a high-level block diagram illustrating selected nodes,server, and PBX of a Multiple Nodes Scalability messaging systemconfigured in accordance with one or more aspects of the presentinvention;

FIG. 3B is a high-level block diagram illustrating selected nodes,server, and PBXs of a Campus Environment messaging system configured inaccordance with one or more aspects of the present invention;

FIG. 4 is a high-level block diagram illustrating selected elements usedfor configuration data processing in a messaging system configured inaccordance with one or more aspects of the present invention;

FIG. 5 is a high-level block diagram illustrating selected elements usedfor local store message processing in a messaging system configured inaccordance with one or more aspects of the present invention;

FIG. 6 is a high-level block diagram illustrating selected elements usedfor groupware store message processing in a messaging system configuredin accordance with one or more aspects of the present invention;

FIG. 7 is a high-level block diagram illustrating selected elements usedfor mailbox processing in a messaging system configured in accordancewith one or more aspects of the present invention; and

FIG. 8 is a high-level block diagram illustrating selected elements usedfor message processing in a messaging system configured in accordancewith one or more aspects of the present invention.

DETAILED DESCRIPTION

In this document, the words “embodiment,” “variant,” and “configuration”refer to particular apparatus, process, or article of manufacture, andnot necessarily to the same apparatus, process, or article ofmanufacture. Thus, “one embodiment” (or a similar expression) used inone place or context can refer to a particular apparatus, process, orarticle of manufacture; the same or a similar expression in a differentplace can refer to a different apparatus, process, or article ofmanufacture. The expression “alternative embodiment” and similar phrasesare used to indicate one of a number of different possible embodiments.The number of possible embodiments is not necessarily limited to two orany other quantity. Characterization of an embodiment, variant,apparatus, process, or article of manufacture as “exemplary” means thatthe item so characterized is used as an example. Such characterizationdoes not necessarily mean that the embodiment, variant, apparatus,process, or article of manufacture is preferred over other such items;the embodiment, variant, apparatus, process, or article of manufactureso characterized may but need not be currently preferred over other suchitems.

A “node” of a messaging system is generally understood as a subsysteminterconnected with other such subsystems of the messaging system,providing messaging services (e.g., receiving, creating, sendingmessages) to a particular subgroup of its associated subscribers, andpossibly to other subscribers of the system, or to all of the system'sassociated subscribers. The messages may include telephone calls,facsimiles, email, and SMS messages. When all nodes are connected to onePBX for scalability purposes, for example, any subscriber may beserviced by any node. See also the discussion in the previous section.

The word “subscriber” signifies a person who can receive and sendmessages using a particular messaging system. Generally, a subscriberhas a preexisting association with the system. For example, a subscribermay be an employee of an organization using the messaging system. A“subscriber” may be able to place a telephone call or otherwise log(from the messaging system or remotely) into the messaging system, andaccess at least limited functionality of the system.

A “mailbox” or a “digital networking mailbox” is a link or addressabletarget for sending and forwarding messages within a networked messagingsystem, such as a voice messaging system. Mailboxes are described inmore detail in a commonly-assigned U.S. patent application Ser. No.11/126,624, entitled Messaging System Configurator, filed on May 11,2005, which application is incorporated by reference herein in itsentirety, including figures, tables, and claims.

“System configuration information” is a collection of settings that havebeen chosen to customize a messaging system for specific needs andapplications. Such information may include description of and dataregarding external devices and systems to which the messaging system andits nodes are connected. System configuration data may include, forexample, descriptions of brands of PBXs; connection methods to the PBXs;parameters defining the PBX connections; which external email stores areconnected; and properties of the email store connections, such as servernames, logon credentials, and similar data. System configuration datamay also include customizations of the system selected by the customer,such as the features that have been enabled and other parameters thatcontrol the system. “Subscriber information” is a collection ofproperties of a subscriber that may be settable (selectable) byadministrators, the subscriber, or both. These properties include itemssuch as the subscriber's name, mailbox number, extension, password,recorded name, recorded personal greeting(s), notification settings,find me and follow me settings used for forwarding a call to aparticular targeted subscriber, class of service, individually enabledfeatures, and similar settable items. Generally, administrators andsubscribers running applications to view or change configuration orsubscriber information settings access a system's core, either directlyor through a connection to core services. Administrators control systemconfiguration and management functions relating to the system.

“Inter-system message networking” refers to the ability to send amessage from one voice mail system to another voice mail system, asopposed to message networking within the same multi-node system such asthose illustrated in FIG. 3A and FIG. 3B and in the commonly-assignedU.S. patent application Ser. No. 11/126,624, entitled Messaging SystemConfigurator, filed on May 11, 2005. In contrast to a multi-nodemessaging system, different voice mail systems may run independentlywith each system having its own set of subscribers and PBX connections,and each system may be owned and/or operated by a different company.

“Status monitoring” and similar expressions refer to monitoring theoperating condition of the system, e.g., monitoring and displaying linestatus that shows which phone lines are in use, by whom, and for howlong. “Health monitoring” refers to monitoring of the nodes of amulti-node system to determine whether the nodes are operating properly.

“Hot standby” refers to a contingency or fallback approach tomaintaining system or component (e.g., node, server, or PBX)availability, whereby a second system/component, with the sameconfiguration as the main system/component is kept running, possibly“mirroring” the processing of the main system/component, ready to takeover the processing load instantaneously in response to a failure of themain system/component. “Warm standby” refers to a method of maintainingredundancy in which the secondary (or backup) system or component runsin the background of the primary system/component. Data is mirrored tothe secondary system/component server at regular intervals, which meansthat there are times when both servers do not contain the exact samedata. “Failover” denotes the capability to switch over automatically toa redundant or standby system or component of a system upon failure orotherwise abnormal termination of the previously active system orcomponent. Failover operation takes place without human intervention andgenerally without warning.

The words “couple,” “connect,” and similar expressions with theirinflectional morphemes do not necessarily import an immediate or directconnection, but include connections through mediate elements withintheir meaning.

“Campus environment” refers to a site with multiple buildings on asingle real estate parcel, or closely spaced real estate parcels, inwhich there may be one or more PBXs. Typical campus environment examplesinclude a university, school, large corporation, and hospital sites.

“Posting” is the process of delivering a message. This process mayinclude the act of making the message available in the subscriber'smessage list. This term may also include the ancillary processes, suchas turning on a message waiting indicator (MWI), sending a messagenotification (callout, SMS, email, etc.). It may also include theprocess of expanding distribution lists to deliver the message tomultiple recipients identified on the list, depositing the message in anemail store if the subscriber is using server-based unified messaging,or passing the message off to the networking module for delivery to aremote system.

In the context of messages store and message storage, “local” means thatthe messages are stored in the native message store of the messagingsystem. Subscriber accounts may be configured to use either local storeor groupware store, depending on specific needs; there is no requirementthat a single message store be used system wide.

“MMC” refers to Microsoft Management Console, which is Microsoft's mainadministrative application.

“AD” and “Microsoft Active Directory” refer to Microsoft's directoryservice.

“SOAP” refers to Simple Object Access Protocol, a technology forpackaging web service requests and responses; a SOAP server is a webservice/server that serves up an embodiment's administrative andoperational data, e.g., messages.

“Private branch exchange” (PBX) is generally understood as telephoneswitching equipment or a telephone exchange that serves a particularbusiness or office. These terms encompass “private automatic branchexchanges” (PABXs). A PBX may be, for example, circuit switched, andInternet Protocol based. Some PBXs support both circuit and IP switchingwithin the same equipment. Other PBXs are also possible.

Other and further definitions (both explicit and implicit) andclarifications of definitions may be found throughout this document. Allthe definitions are intended to assist in understanding this disclosureand the appended claims, but the broad scope of the invention should notbe construed as strictly limited to the definitions, or to theparticular examples described in this specification.

Reference will now be made in detail to several embodiments of theinvention that are illustrated in the accompanying drawings. Same orsimilar reference numerals may be used in the drawings and thedescription to refer to the same or like items. The drawings are insimplified form, not to scale, and omit apparatus elements and methodsteps that can be added to the described systems and methods, whilepossibly including certain optional elements and steps.

FIG. 1 is a high-level block diagram of an exemplary node 100 of aunified messaging system that can be used to implement processesdescribed in this document. The node 100 may be a non-core node, or acore node that also provides functionality of non-core nodes. The node100 includes telephony interfaces 128 that couple the node 100 to anetwork 136 and to switching equipment 130. In the embodimentillustrated in FIG. 1, the switching equipment 130 is a circuit switchedPrivate Branch Exchange (PBX), while the network 136 is a publicswitched telephone network (PSTN). In other embodiments, the switchingequipment may be of a different kind, for example, an IP PBX, anautomatic call distributor or ACD, central office switches, and possiblypeer to peer IP switches. (ACDs are often found in offices that handlelarge volumes of incoming phone calls from callers who have no specificneed to talk to a certain person, but want to talk to a person who isready to serve at the earliest opportunity.) The network 136 can be, forexample, the Internet, an intranet, an extranet, a virtual privatenetwork (VPN), a local area network (LAN), a wide area network (WAN), anenterprise network, or a private switched network. The network 136 maybe coupled to cellular radio networks, such as the wireless network 145,so that the unified messaging system of which the node 100 is a part canreceive inbound calls from cellular telephones and other mobile devices(e.g., mobile device 147), and place outbound calls to such mobiledevices.

The node 100 may be able to interface simultaneously with severaldifferent networks, such as the networks listed above. The node 100 mayalso interface with several different switches. For example, the unifiedmessaging system may be connected at the same time to a public switchedtelephone network and to a LAN, WAN or Internet, managing (1) Voice overInternet Protocol (VoIP) calls switched by an Internet Protocol PBX, (2)PSTN calls switched by a conventional circuit switched PBX, (3)receiving and sending email through an email server, (4) receiving andsending IM messages through an IM server, and (5) receiving and sendingSMS messages through an SMS server. The PBX 130 and/or other switchingequipment may be included in the node 100.

Returning to the embodiment illustrated in FIG. 1, the telephonyinterfaces 128 may include analog, digital, and VoIP trunks or stations.A switching matrix 126 is interposed between the telephony interfaces128 and other components of the node 100, selectively connecting inboundand outbound calls between various constituent components of the node100. In addition to the switching matrix 126 and the telephonyinterfaces 128, the constituent components of the node 100 include aprocessor subsystem 102, a dual tone multi-frequency (DTMF) decoder 104,a DTMF generator 106, an interactive voice response (IVR) module 110, anaudio digitizer 112, a media (audio) recorder 116, an automatic speechrecognition (ASR) module 118, a media (audio) playback device 120, atext-to-speech converter 122, and a data server interface 124.

The processor subsystem 102 may include one or more processors withsupporting circuitry and chipsets, such as microprocessors, memories,and interface circuits that are known to a person skilled in the art. Inone embodiment, the processor subsystem 102 includes a general purposemicroprocessor and a digital signal processor (DSP). The processor orprocessors of the subsystem 102 execute program code stored in one ormore memories. The code may be loaded from another machine-readablemedium, such as a CD, DVD, flash memory, floppy or hard drive, or asimilar device. The code may also be loaded via a network.

The processor subsystem 102 is coupled to an email server 150 and anIM/SMS server 160, to enable the subscribers of the unified messagingsystem to send and receive email messages and instant/SMS messagesthrough a LAN or wide area network 170 (e.g., the Internet). The node100 may also use the network 170 to communicate with other nodes of theunified communication system, including both core and non-core nodes.SMS messages may also be sent through a cellular telephone device, whichmay be directly connected to the system using, for example, a serial orUSB connection.

The DTMF decoder 104 detects dual tone multi-frequency signals intelephone calls and generates corresponding signals readable by theprocessor subsystem 102. For example, an external or outside caller(which caller may also be a subscriber) can input DTMF signals from thekeypad of the telephone 140 when asked by the IVR module 110 to make amenu selection. In response to the DTMF signals, the processor subsystem102 may cause the node 100 and the system of which it is a part toperform the functions selected by the caller. Voice input can be usedinstead of or in addition to the DTMF input.

The DTMF generator 106 generates DTMF signals under control of theprocessor subsystem 102. For example, an Automated Attendant system mayplace an internal call when an outside caller requests a specificsubscriber, to transfer the caller to the subscriber's extension. Asanother example, the node 100 may generate the DTMF signals to place anexternal call. The node 100 may place the external call for a subscribercalling from outside, so that subscribers who are traveling can call andlog into the node 100, and have their calls placed from the node 100 ormore generally from the messaging system to which the node 100 belongs.External calls may also be placed when the node 100 implements a “CallMe Back” feature, which allows a subscriber to call and log into thenode 100, and have the system immediately call the subscriber back at adesignated number, thereby lowering the subscriber's telecommunicationcharges (e.g., air time and long distance charges). Land lines, most ofEuropean cellular network operators, and certain U.S. cellular networkoperators do not charge for incoming calls. As still another example,the node 100 may generate DTMF signals when placing an external call tonotify a subscriber regarding messages left for the subscriber. Themessages may include, for example, voicemail messages, facsimilemessages, email messages, instant messages, SMS messages, andpreprogrammed reminders.

The IVR module 110 automates certain interactions between the callersand the node 100. Interactive voice response can provide audio promptsto request information and store responses from a caller. The responsescan be in the form of touch-tones generated by pressing telephone keys,or voice responses. Voice responses may be converted to digitalinformation by voice recognition signal processing of the ASR module118. Interactive voice response may be used for automatic calldistribution or service activation or changes. If the caller is asubscriber, the node 100 may use the IVR block 110 to verify thesubscriber's identity, and then play received and stored messagesintended for the subscriber, as well as notify the subscriber ofreceived email, facsimile, and other messages. The node 100 may alsoallow the subscriber at a remote location to change answering andforwarding options, as well as other subscriber-specific data. For othercallers, the node 100 may provide interactive functionality foridentifying a proper recipient for the call, and navigating among thevarious extensions available on the PBX 130 or more generally on themessaging system to which the node 100 belongs.

The digitizer 112 converts received analog audio signals into digitalform.

The media recorder 116 stores the audio signals, under direction of theprocessor subsystem 102. For example, the media recorder 116 may recordmessages left by callers for the subscribers of the node 100 or of themessaging system. In one embodiment, the media recorder 116 includes aninterface to mass storage devices, such as an interface to a redundantarray of inexpensive disks (RAID). The mass storage devices may be apart of the node 100 or of the unified communication system, or beseparate from the node 100 and the messaging system.

The ASR module 118 recognizes spoken words and phrases in audio streamsof telephone calls, and generates corresponding signals readable by theprocessor subsystem 102. The ASR module 118 may be used in conjunctionwith the IVR module 110 to interpret callers' voice input to the node100. In response to the menu selections offered by the IVR module 110, acaller can speak the desired selections, such as name or extensionnumber of the called (target) party. The ASR module 118 identifies thename or the extension number (or another selection) from the spokenwords, and sends corresponding signals to the processor subsystem 102.The processor subsystem 102 then causes the node 100 or the system toperform the functions selected by the caller, for example, connectingthe caller to the targeted person or extension.

The media playback device 120 plays audio files to the callers andsubscribers. For example, the playback device 120 may include aninterface to the mass storage devices used by the media recorder 116.The playback device 120 can access the messages stored by the mediarecorder 116, and play the messages to the subscribers upon request andafter proper identification.

As implied by its name, the text-to-speech converter 122 converts textinto speech. The text-to-speech converter 122 may enable a subscriber ata remote location to access (over a telephone connection or theInternet, for example) facsimile, email, and other messages sent to thesubscriber and received by the system, where textual information isconverted to its synthesized spoken equivalent.

The data server interface 124 provides access to various data files thatmay be used by the node 100 or requested by the subscribers or callersof the node 100. The data available for retrieval through the dataserver interface 124 may include, for example, subscriber groupwareinformation, such as email, contacts, and calendar entries. The dataserver interface may also store and retrieve customer orders, andprovide corporate data to the callers. In one example, the data serverinterface 124 includes interfaces to Microsoft Exchange® and LotusDomino® servers. The data server interface 124 may be connected to thenetwork 170.

The DTMF decoder 104, the IVR module 110, and the ASR module 118 mayalso be used when a subscriber sends email and IM/SMS messages from theunified communication system.

It should be noted that the various modules illustrated in FIG. 1 can beimplemented in hardware, in software, or as a combination of hardwareand software components. For example, the DTMF decoding and automaticspeech recognition functions of modules 104 and 118 may be performed bythe digital signal processor or another processor of the processorsubsystem 102. The lines dividing the various modules of the node 100 inFIG. 1 (and similar lines in other Figures) should therefore beunderstood as logical dividers used mainly for illustration and ease ofdescription at a relatively high conceptual level.

For certain additional details of the node 100, see commonly-assignedU.S. patent application Ser. No. 10/932,745, entitled Apparatus andMethod for Personalized Call Acknowledgement, filed on Sep. 2, 2004,which application is incorporated by reference herein in its entirety,including figures, tables, and claims.

FIG. 2 is a high-level block diagram of a unified messaging system 200configured in accordance with embodiments of the present invention, asis more fully described throughout this document. The system 200includes a single core node 210, a plurality of non-core nodes 220, andone or more PBXs 230. The core node 210, non-core nodes 220, and the PBX230 may be interconnected through wide area and telephone networks asshown in FIG. 1 (the networks 170 and/or 136). The arrows 240 shownetwork interconnections between the system components, for example,interconnections through the LAN or wide area network. (PBX connectionsmay be circuit switched or IP.)

The core node 210 (or simply the “core”) is configured to provide acentral repository for system configuration information and subscriberinformation. The core node 210 is also configured to provide centralizedadministrative and subscriber access to configuration and subscriberinformation. The core node 210 is further configured to provide othercentralized services, such as notification of received messages,inter-system message networking, and status monitoring, some of whichmay not be appropriate for duplication on multiple or all of the nodes(i.e., functions that are not appropriate to be running individually onthe individual non-core nodes, and that are centralized functionsrunning on the core). Still further, the core node 210 may be configuredto provide functions of a non-core node.

An exemplary non-core node 220 (e.g., 220-1, 220-2, . . . 220-N) isconfigured as a platform for running telephony user interface (TUI)and/or voice or speech user interface (VUI) applications which processcalls and other messages. TUI generally refers to the interface foruser/subscriber or caller interactions with the telephone system,typically through an automated phone system with keypad responses, whichmay use the DTMF decoder and IVR modules. VUI generally refers to theinterface for user/subscriber or caller interactions with the telephonesystem through voice/speech platform, which may use the ASR and IVRmodules. The communications between and among non-core nodes and betweenand among core and non-core nodes may be effected through InternetProtocol (IP) connections, such as the connections 240. The unifiedmessaging system may be configured on a LAN/WAN that is fast enough toprovide for real time access to data from the core node during normaloperation.

All software components may be run on a single node which contains bothcore and non-core node elements.

The core node 210 may contain and be configured for thecomponents/applications/services on the following non-exhaustive list:

1. One or more databases and one or more database servers.

2. One or more data service module(s) that provide applicationprogramming interfaces (APIs) for application access, implement businessrules, and read/write data to databases and/or one or more groupwareservers.

3. One or more modules for message notification processing services, forexample, an SMS notification service that sends notifications using acellular modem, sending SMTP email notifications, and a centralnotification server that allocates notification callout activity tovarious nodes that have appropriate phone lines for execution.

4. One or more networking service modules, such as an inter-systemnetworking module for inter-system voice mail networking, whichimplements communication protocols with foreign voice mail systems (insome embodiments there is only one of these modules per system).

5. One or more system control and health monitoring modules, such asline status monitoring, health monitoring, and diagnostic monitoring.

6. Call and other event scheduling modules (such as daily maintenanceactivity scheduling, which may include backup, synchronization withthird party services, speech recognition grammar management,auto-deletion of aged messages, database maintenance, automatic reportgeneration, and callouts for notification).

7. One or more administrative configuration interfaces. One embodimentincludes a primary administrator interface that is used byadministrators to configure features, create mailboxes, and for similaractivities. This embodiment also provides a report interface for reportgeneration, a diagnostic interface, support for third partyadministration applications for configuring the system, and support formultiple interfaces that allow subscribers to control the options oftheir respective mailboxes.

8. One or more web servers.

9. One or more backup/restore/archive service modules.

10. One or more administration and reporting applications. Theseapplications may be run on a separate client system. In one embodimentsuch applications include a locally-run Control Panel application forbase system setup, which runs only locally; and a remotely-run primaryadministration GUI, which is mostly for subscriber administration.Administration applications/interfaces may also allow other applications(both of the messaging system on which they are implemented and of thirdparty systems) to administer subscribers. This may include an MMCSnap-In to the Microsoft Active Directory administration tool, whichallows for subscriber administration. Reports, line status display, andDiagnostics applications may also run on a remote client.

Note that not all core components are required in all configurations,and that core components may be distributed to multiple physicalservers, either co-located or not.

In some variants, the core node 210 is built on a high availabilityserver to limit possible down time. This could be a Stratus non-stopcomputing system, or servers configured for Microsoft® cluster server.

A core or a non-core node may contain and be configured for thecomponents/applications/services on the following non-exhaustive list:

1. One or more circuit switch telephone interfaces.

2. One or more IP telephony interfaces.

3. One or more PBX integration interfaces.

4. One or more TUI applications.

5. One or more VUI applications.

6. One or more speech recognition services/modules.

7. One or more databases and one or more database servers withreplicated databases.

8. Local cache management for caching of audio recording, such as spokennames, greetings, and messages.

9. Local line management applications. Telephone line management andcontrol may include on/off hook control, detector of telephony signals(DTMF, hang up, call progress, etc.), audio player (media playbackdevice) and media recorder, text to speech converter, and ASR.

10. Local access to an external groupware store.

Not all node components are required in all configurations.

In some variants, each node is located in proximity of its associatedPBX, for example, located within the same building, to enable serial ordigital station set connections between the node and its associated PBX.In some variants, each node includes its associated PBX.

Some or all of the configuration and subscriber data may be replicatedfrom the core node 210 to one or more non-core nodes 220, or to all ofthe non-core nodes 220. Replication may be performed in real-time ornear real-time, periodically (in equally spaced time intervals),sporadically, or otherwise. (Real or near real-time replication heremeans that in most cases a database update will be replicated by thetime someone next has a use for the database data; in the case of speechdata, in some embodiments, the delay can be up to one or two secondsthat may be needed to retrieve a recording from the core prior tostarting playback.) Individual non-core nodes may rely on the replicateddata to present user/subscriber services that do not involve theupdating of the configuration and/or subscriber data. In some variants,individual non-core nodes 220 rely on the replicated data to provide allservices that do not involve the updating of the configuration orupdating of the subscriber data. This scheme allows the non-core nodes220 to continue to send, receive, and process calls and other messageswhen the core node 210 is not available due to system failure,communications failure, maintenance activities, or other reasons. Forexample, if the non-core node application is an automated attendant, thenon-core node can route a call (or another message) to the appropriatesubscriber without relying on the core node, possibly including routingthe call (or message) to a subscriber at another node or extension on aPBX associated with a different non-core node. As another example,non-core nodes can take messages from callers when the core node is notavailable. The messages may be queued for posting and delivery when thecore node becomes available again. Moreover, a single logical unifiedcommunication system with nodes associated with individual PBXsdistributed in a campus or wider area may be formed. Each individualnode may be closely distributed next to the PBX(s) with which the nodeis associated, while maintaining a single logical system. The non-corenodes may use the replicated configuration and/or subscriber data evenwhen the core node 210 is available; this, feature, however, is not arequirement, so that the non-core nodes may use the configuration andsubscriber data from the core when the core is available,notwithstanding the availability of the replicated data on the non-corenodes.

In some variants, the non-core nodes may also master their own databasesand be semi-autonomous. In other words, database updates may be allowedto semi-autonomous nodes without going through the core node databaseserver. For example, a message may be posted on a particular non-corenode, but the message may not be available for access from other nodes.This would be useful in the situation where the particular node is in adifferent city or building on a campus and messages are seldom sent tosubscribers outside of the building.

The non-core nodes 220 may be configured directly to access messages,calendar, and contact information from external groupware applications.This configuration allows each of the non-core nodes 220 to continue toprovide access to the groupware information when the core node 220 isunavailable. Message requests, calendar requests, and other groupwarerequests may be made to groupware directly from the non-core nodes 220,allowing the non-core nodes 220 to continue to provide full or partialservice even when the core node 210 is unavailable.

Each of the nodes 220 may be configured to operate independently ofother nodes. If a node 220 fails in this configuration, the operation ofother nodes need not be affected, allowing the system to continue tooperate, possibly in a reduced capacity mode.

The unified messaging system and its nodes 220/210 may be configured toprovide node failover, depending on the ability to redirect phone lines(the ability to redirect phone lines is generally a function of thePBX). For example, if a node 220-1 fails, its associated phone lines maybe redirected to another node, for example, 220-2 or 210. Hot standbyand warm standby may also be available. In this way, multiple nodes maybe used to construct a large scale unified messaging system with itsreliability enhanced by the use of multiple nodes, eliminating orreducing the system's vulnerability to a single point of failure.Because the replicated data at a particular node 220 may be used whenproviding service to subscribers and outside callers, the subscribersand the callers may access the node for service even when the core node210 is down. Furthermore, with failover capability, subscribers andoutside callers may continue to access those subscribers servedprimarily by a failed node (either core or non-core). In a large scalesystem where multiple nodes are connected to the same PBX forscalability, there may be no relationship between a subscriber and anon-core node since any non-core node may answer a call on behalf of thesubscriber.

A single logical system, such as the unified messaging system 200, maybe constructed to span a campus or a wider area (with nodes and PBXs indifferent cities, for example) by placing nodes at the various PBXinterface points, some or all of the non-core nodes being connected to asingle core node. This allows for a single unified messaging orcommunications system to serve multiple PBXs at multiple locations. Thecomponents of the core node such as the node 210 may be distributedamong multiple computer systems.

Data replication, node failover procedures, and additional backupprocedures can be used to keep a standby site up to date for disasterrecovery situations, such as a complete failure of the core node 210.

Not all of the data may need to be replicated. Certain data may or maynot be replicated. In some embodiments, replicated data includessubscriber information and system configuration information, while notreplicated data includes message information, machine configuration,schedule, and MWI database. On demand or subscriber-selectablereplication may include recordings of messages, greetings, andsubscriber and other names.

The system 200 is configured to allow a person logged in asadministrator to add, change, and delete system configuration byinteracting with the core components of the core node 210. Some of theconfiguration data may be also added, changed, or deleted by a personlogged in as a subscriber. Generally, a non-administrator subscriber maybe enabled to edit (i.e., add, change, delete) the information thatrelates to the subscriber and does not affect other subscribers orsystem operation as a whole. An administrator may be enabled to edit allconfiguration data. Several levels of administrative privileges may alsobe provided. Updates made by subscribers at the non-core nodes 220 maybe written directly to the core node 210. If the core node 210 isunavailable, updates may be disallowed or queued, depending on the typeof the particular update. Messages left for a targeted subscriber may bequeued locally on the particular non-core node 220 associated with thetargeted subscriber, and then sent to the core node 210 for posting.Groupware access may be processed directly at each non-core node 220,without involving the core node 210. This includes access and updates tothe groupware information. If the core node 210 is unavailable, in somevariants message posting and notifications triggered by groupware accessmay not be processed until the core node 210 becomes available.

Some embodiments do not normally queue updates, because if the callercalls back and attempts to change the queued item again, the queuedupdate is not reflected in the state of the item that the user thinks isbeing changed. In some cases where data integrity can be assured (andtherefore user confusion avoided), queuing may be implemented. It isgenerally safe to queue incoming messages because users will not see themessages until the messages are delivered through the core node.

For certain additional configuration data details andadministrative/subscriber editing of configuration data, see thecommonly-assigned U.S. patent application Ser. No. 11/126,624, entitledMessaging System Configurator, filed on May 11, 2005.

FIG. 3A illustrates selected nodes, server, and PBX of a messagingsystem 301, referred to as a Multiple Nodes Scalability system, andconfigured with data replication as described above. The system 301includes a core node 310, two non-core nodes 320A and 320B, a PBX 330,and a groupware server 345. Each of the nodes 310/320 may be configuredas has been described above in relation to the nodes 210 and 220 of FIG.2, and the node 100 of FIG. 1. Here, both non-core nodes 320A/B areserved by a single PBX 330.

In the system 301, the core node 310 contains a database, administrationinterfaces, and a graphical user interface for client access support.Each of the non-core nodes 320A/B contains connections to phone lines, areplicated database, temporary message storage, and an interface to thePBX 330. The core node 310 may have phone lines, or be implementedwithout phone lines. The groupware server 345 is used for unifiedmessaging and access to groupware calendar and contacts.

The single PBX feature is not a requirement of the invention. Thus, FIG.3B illustrates selected blocks of a messaging system 351, referred to asCampus Environment System, which is also configured with datareplication as described above. The system 351 includes a core node 360,three non-core nodes 370A/B/C, PBXs 380A/B, and a groupware server 395.Each of the nodes 360/370 may be configured as has been described abovein relation to the nodes 210 and 220 of FIG. 2, and the node 100 ofFIG. 1. Here, the PBX 380A is connected to and normally providesservices to subscribers at the non-core nodes 370A and 370B, while thePBX 380B is connected to and normally provides services to thesubscriber at the non-core node 370C.

In the system 351, the core node 360 contains a database, administrationinterfaces, and a graphical user interface client access support. Eachof the non-core nodes 370A/B/C contains phone lines, a replicateddatabase, and temporary message storage. The non-core nodes 370A/B/Csupport phone lines and interface to the PBXs 380A/B. The core node 360may have phone lines, or be implemented without phone lines. Thegroupware server 395 is used for unified messaging and access togroupware calendar and contacts.

FIGS. 4, 5, and 6 illustrate selected aspects of, respectively,configuration data processing, local (here used in the sense ofnon-groupware) store message processing, and groupware store messageprocessing in an embodiment. As shown in FIG. 4, core configuration datastore 411, data replication service 412, core database service 414, andcore administration services 415 may reside on a core node 410; the corenode 410 may be the same as the core nodes 210 and 310 discussed above.Node configuration data store 421, node database service 422, nodeadministration access services 426, and TUI/VUI applications 424 mayreside on a non-core node 420; the non-core node 420 may be the same asthe non-core nodes 220 and 320 discussed above.

To edit the configuration data of the unified communication system, asubscriber without administrative privileges may access the coreadministration access services 415 by using subscriber GUI clientapplications 491; similarly, a person with administrative privileges mayaccess the core administration access services 415 by usingadministration GUI client applications 492. The GUI client applications491 and 492 may reside remotely and access the core node 410 via anetwork, for example, a LAN or the Internet. Configuration data may alsobe edited by a subscriber or administrator logged into the non-core node420, through the node administration services 422 and TUI/VUIapplication 424. The administration access services 415 receive theconfiguration updates from the GUI client applications 491/492 or fromthe node administration access services 426, and in response update thecore configuration store (database) 411 through the core databaseservice 414. The replication service 412 replicates the configurationdata from the core configuration store 411 to the non-core nodeconfiguration stores such as the store 421. This may be doneincrementally, for example, by distributing only the updates;replication may be done in real-time or near real-time, periodically,sporadically, or otherwise. The TUI/VUI applications 424 receive theconfiguration updates through the non-core node database service 422.

As shown in FIG. 5, the core node 410 further includes a core messagestore 441 for storing subscribers' messages (which are accessiblethrough the database service 414), a core message access service 445,and a core message posting service 443. The core node 410 furtherincludes notification services 442, which accept and send outnotification events 447 and notification event cancellations 448.

The non-core node 420 includes a node pending message store 431 forstoring pending messages, i.e., messages not yet posted to the coremessage store 441. The non-core node 420 also includes a node postservice 432 for posting the messages of the node 420 from the node store431 and to the core message store 441 (through the message postingservice 443). The non-core node 420 further includes node message accessservice 433, which makes the messages stored in the message stores 431and 441 accessible through the TUI/VUI applications 424 and thesubscriber GUI client applications 491.

FIG. 6 illustrates additional components of the nodes 410/420 that areused for accessing groupware services and store 451. The non-core node420 includes a groupware access service 452 connecting the groupwareservices and store 451 to the node message access service 433 and to thenode post service 432. The core node 410 includes groupware notificationprocessing service 453 for receiving groupware notification informationand transmitting the information to the notification services 442.Additionally, the groupware services and store 451 are connected to themessage posting service 443.

FIG. 7 illustrates selected aspects of mailbox processing in anembodiment that includes the core node 410 and the non-core node 420,configured to put into operation one, several, or all features of thefollowing Model Consensus:

1. A single authoritative directory store resides on the core node. Thedirectory is authoritative in the sense that the changes to theinformation stored must be first posted to the authoritative core nodedirectory, before the changes are propagated (e.g., replicated) to thenon-core nodes. Thus, the core node directory is a master storagelocation from which all other subordinate locations obtain their data,after the data are posted on the core node directory. (Posting may bedone from a non-core node to the core node.)

2. The core directory can be maintained through the Microsoft ManagementConsole (making the Microsoft Active Directory a pseudo master), orother external administration programs through the SOAP interface.

3. Mailbox updates are not allowed if the core node 410 is down orotherwise unavailable to the non-core nodes.

4. Read access is accomplished through SQL calls to the local nodestore. SQL calls are covered by a local object.

5. Mailbox updates are posted directly to the core node 410 through theSOAP server. This configuration provides the ability to trigger back-endprocessing, such as IMN changes. (IMN may be a function of messageposting, not subscriber updates, although a subscriber update couldcancel a pending IMN. Most subscriber back-end processing is generallyrelated to deleting a subscriber, which may cause messages to bedeleted, the subscriber is removed from distribution lists and otherreferences may be removed. In some cases some back-end processing occurswhen a subscriber is updated as in the IMN case described above.) “IMN”refers to Immediate Message Notification—callouts to telephones, pagers,and similar subscriber personal communication devices, to notify arecipient (subscriber) of receipt and/or availability of a new message.

6. Mailbox information is replicated to non-core nodes (such as the node420) to support auto attendant, call answering, and personal assistantfunctions when the core node 410 is down or otherwise unavailable to thenon-core nodes.

7. Just-in-time retrieval of names, greetings and announcements from thecore by non-core nodes is supported. Non-referenced recordings do notnecessarily reach a non-core node. Non-referenced recordings are thoserecordings that have never been requested by an application running on aspecific node. In this specification, just-in-time means when therecording is requested by a user/subscriber for playback. The recordingsare delivered to nodes when they are requested, rather than when theyare created. In other words, in this embodiment, a recording isdelivered to a node in response to being requested by or from the node,instead of being delivered to the node in response to being created. (Insome other embodiments, recordings could be delivered to nodes when therecordings are created.)

8. The embodiment is conservatively implemented, maximizing the use ofexisting services/code. The embodiment also implements hooks to redirectupdate requests to core node SOAP server from non-core node SOAP server.Some or each of the non-core nodes have own SOAP servers, with the localapplications making requests to the local node SOAP server. The localSOAP server decides if the received request can be executed locally, orshould be passed on to the core node SOAP server for central execution.For example, looking up a subscriber to verify that a message may besent may be done locally (here meaning within the same node) withreplicated data. Posting of a message may be redirected to the corenode, so that core functionality can be invoked. Applications need nothave knowledge of this process, so they may run without change on asingle server node+core system, or on a multi-node system.

In certain variants of the embodiment of FIG. 7, the communicationsystem is configured to implement one, several, or all of the followingfeatures:

1. Administrator's deletion of a subscriber causes all messagesassociated with the deleted subscriber to be deleted. Subscriberdeletion also causes deletion of distribution list references, pendingnotifications, and other operational state data related to the deletedsubscriber.

2. Most server applications do not directly access the subscriberdatabase. All server applications do not directly access to the localcopy of the database. Thus, the database is accessed indirectly throughthe SOAP server that allows (1) redirection of requests to the core ifneeded (i.e., selectively), and (2) implementing business rules that areconsistently applied across the system.

3. Updates by non-core node based clients are written directly to thecore node. Local applications cache mailbox properties, rather thanreading a possibly out of date version from the local store.

4. Updates are properly sequenced to maintain referential integrity.Master mailbox record (on the core) updates first, deletes last.Referential integrity refers to sequencing changes to a database so asnot to cause the database to become corrupted.

Each of the nodes 410/420 may be configured as has been described abovein relation to the nodes 210 and 220 of FIG. 2, and the node 100 of FIG.1.

FIG. 8 illustrates selected aspects of message processing in anembodiment that includes the core node 410 and the non-core node 420,configured to put into operation one, several, or all of the features ofthe following Model Consensus:

1. A single authoritative message store resides on the core node. Themessages are not replicated.

2. When the core node 410 is down, local store messages are notaccessible.

3. Local store messages are posted through the core post process so thatthe messages first appear in the authoritative message store (of thecore); and so that centralized services such as voice mail networkdelivery, MWI, IMN, SMS and other centralized activities triggered bythe posting of the message are initiated. Also implemented aredistribution list expansion, network delivery, and similar features.

4. Node SBUM access may be through a local MTA. (“SBUM” refers to ServerBased Unified Messaging, i.e., unified messaging where the message isstored in the third-party application email store, such as MicrosoftExchange, IBM/Lotus Domino, or Novell Groupwise store; “MTA” refers tomessage transfer agent.) The MTA may access groupware stores. The MTAmay run on both the core node 410 and the non-core node 420. The systemmay be configured to enable retrieval of messages from the groupwareeven when the core node 410 is down. SBUM may be configured for postingmessages through master post, with possible exceptions of replies andforwards where a local message context is required. Local messagecontext may be required in cases where, when logged on to an emailstore, a reply or forward email must be sent within the same connectsession with the email store, in order for the reply or forward to beproperly identified within the email store.

5. Calendar posting and contact updates to groupware servers may be donelocally. Here “locally” refers to the non-core node associated with aparticular subscriber.

6. When the core node 410 is down or otherwise unavailable, callanswering and personal assistant messages may be taken and queuedlocally (here meaning on the node receiving the particular message)until the core node 410 comes back up.

7. SBUM or local store is implemented on a subscriber-by-subscriberbasis.

8. Posting to SBUM store may be done when the core node 410 is down.(For example, this may be done where the recipient is a SBUM user andnotifications are through SBUM.)

The embodiment of FIG. 8 may include all the features described inrelation to the FIGS. 4-7. Some of the blocks in FIG. 8 are the same assimilarly or identically designated blocks shown in FIGS. 4-7. Asregards to the MTA blocks, each represents an external email stateinterface service. The scheduler block represents a scheduling servicethat maintains a schedule of time-constrained and/orresource-constrained tasks, and initiates the tasks at appropriatetimes, including, for example, message notification callouts and dailymaintenance activity. The ICA Server provides IMAP service, a servicethat offers an IETF standard IMAP interface through which GUI and otherclients can access messages in the non-groupware message store.

In certain variants of the embodiment of FIG. 8, the communicationsystem is configured to implement one, several, or all of the followingfeatures:

1. Administrative deletion of a subscriber may cause all messagesassociated with the deleted subscriber to be deleted.

2. The client message access server may be the SOAP server running in amode to support node applications. On a single server system, same SOAPserver may serve local (of the same node as the server) applications, aswell as remote applications (system wide applications, including thoseon other nodes). Message posting may be handled through this interfaceas well. The message access server may communicate with both the nodepost and core message store.

3. Groupware client access server accesses messages on the groupwareserver. Updates to message properties and message deletion may be donethrough this interface. Messages may be sent through the post process.Groupware client access may also provide access to contacts andcalendar.

4. MTA interface is used to post messages to a groupware store and tohandle store based MWI and immediate message notifications.

5. Node post interface may be identical to the core post interface. In asingle node system there may be one post, while on a multi-node systemthe node post may cache and forward messages to the master post.

6. Non-Delivery Notifications or NDNs are handled consistently andcompletely for cases where posting is unsuccessful.

7. Messages are atomic and normalized. Full SMTP support may beprovided.

As has already been noted, not all components may be needed for allconfigurations. In cases where users are not accessing the system usinga browser interface, for example, web servers may be omitted; for caseswhere local storage only is being used, groupware interfaces may beomitted; and where networking with remote or legacy systems is not used,networking components may be omitted. These are of course merelyexamples of components that may be omitted.

Concepts described in this document may generally apply to servicinglarge numbers of users accessing a messaging system simultaneously wherethere is a central database that requires updating in some cases, butread only access and delayed updating allows for partial availability ofthe system when the central database is unavailable for some reason.

The process steps of the various methods described throughout thisdocument may be illustrated and explained serially. In specificnon-limiting variants/embodiments, the process steps are implemented inthe same order in which they are illustrated and/or explained. Moregenerally, certain steps can be performed by separate elements inconjunction or in parallel, asynchronously or synchronously, in apipelined manner, or otherwise. There is no particular requirement thatthe steps be performed in the same order in which this description liststhem, except where explicitly so indicated, otherwise made clear fromthe context, or inherently required. Furthermore, not every illustratedstep is required in every embodiment in accordance with the invention,while some steps that have not been specifically illustrated may bedesirable or necessary in some embodiments in accordance with theinvention. Each of the steps may encompass several sub-steps.

As a person skilled in the art would know after reviewing this document,data and signals may be represented using any of a variety of differenttechnologies and techniques, including, without limitation, voltages andcurrents. The various blocks, modules, processes, and similarelements/blocks/steps shown in the Figures and discussed throughout thisdocument may be implemented in hardware, software, or combinations ofhardware and software. The elements may be implemented and correspondingsteps performed by general purpose processors, special purposesprocessors, other programmable logic device, or a combination of suchprocessors and devices.

This document describes the inventive apparatus, methods, and articlesof manufacture for implementing a multi-node messaging system inconsiderable detail. This was done for illustration purposes only.Neither the specific embodiments of the invention as a whole, nor thoseof its features limit the general principles underlying the invention.The specific features described herein may be used in some embodimentsand variants, but not in others, without departure from the spirit andscope of the invention as set forth. Various physical arrangements ofcomponents and various step sequences also fall within the intendedscope of the invention. The invention is not limited to the use ofspecific components. Many additional modifications are intended in theforegoing disclosure, and it will be appreciated by those of ordinaryskill in the art that in some instances some features of the inventionwill be employed in the absence of a corresponding use of otherfeatures. The illustrative examples therefore do not define the metesand bounds of the invention and the legal protection afforded theinvention, which function is carried out by the claims and theirequivalents.

What is claimed is:
 1. An article of manufacture comprisingnon-transitory machine-readable storage medium with program code storedin the machine-readable medium, the program code being for operating amulti-node messaging system comprising a core node and a plurality ofnon-core nodes, the plurality of non-core nodes comprising a firstnon-core node and a second non-core node, each non-core node of theplurality of non-core nodes being coupled to telephone switchingequipment associated with said each non-core node, wherein the programcode stores computer instructions for performing steps comprising:configuring the core node to provide central repository services forstoring system configuration of the multi-node messaging system, storingsubscriber information for subscribers served by the multi-nodemessaging system, and providing centralized administrative andsubscriber access to the system configuration information and subscriberinformation; and configuring said each non-core node of the plurality ofnon-core nodes as a platform running telephony user interfaceapplications for processing telephone calls; wherein: at least the firstnon-core node of the plurality of non-core nodes is configured toprovide a platform running voice user interface applications forprocessing the telephone calls; the core node and at least two non-corenodes of the plurality of non-core nodes are configured to replicate atleast a portion of the system configuration information stored on thecore node and at least a portion of the subscriber information stored onthe core node to each non-core node of the at least two non-core nodes;the multi-node messaging system is configured to receive calls and voicemessages from outside callers to the subscribers served by themulti-node messaging system, so that the outside callers are enabled tocall extensions of specific subscribers served by the multi-nodemessaging system selected by the outside callers, and so that theoutside callers are enabled to leave voicemail for the specificsubscribers selected by the outside callers; and the messaging system isconfigured to enable the subscribers served by the messaging system toplace through the messaging system external calls directed outside themessaging system.
 2. The article of manufacture of claim 1, wherein:said portion of the system configuration information comprises allsystem configuration information of the multi-node messaging system; andsaid portion of the subscriber information comprises all subscriberinformation for the subscribers served by the multi-node messagingsystem.
 3. The article of manufacture of claim 1, wherein the stepsfurther comprise configuring the core node and the at least two non-corenodes to replicate the portion of the system configuration informationstored on the core node and the portion of the subscriber informationstored on the core node to the at least two non-core nodes in real-time.4. The article of manufacture of claim 1, wherein the steps furthercomprise configuring the core node and the at least two non-core nodesto replicate the portion of the system configuration information storedon the core node and the portion of the subscriber information stored onthe core node to the at least two non-core nodes substantially inreal-time.
 5. The article of manufacture of claim 1, wherein the stepsfurther comprise configuring the core node and the at least two non-corenodes to replicate the portion of the system configuration informationstored on the core node and the portion of the subscriber informationstored on the core node to the at least two non-core nodes periodically.6. The article of manufacture of claim 1, wherein: the first non-corenode is associated with a first plurality of the subscribers served bythe multi-node messaging system and the second non-core node isassociated with a second plurality of the subscribers served by themulti-node messaging system, the first non-core node being coupled to afirst private branch exchange for servicing the first plurality of thesubscribers, the second non-core node being coupled to a second privatebranch exchange for servicing the second plurality of the subscribers,the second plurality of the subscribers being different from the firstplurality of the subscribers; the steps further comprise configuring thefirst non-core node to receive messages for the first plurality of thesubscribers through the first private branch exchange, thereby obtaininga first plurality of received messages, and posting the first pluralityof received messages on the first non-core node without automaticallyposting the first plurality of messages on the core node, so that thefirst plurality of messages is not automatically available from anynon-core node of the plurality of non-core nodes other than the firstnon-core node.
 7. The article of manufacture of claim 1, wherein: thefirst non-core node is associated with a first plurality of thesubscribers served by the multi-node messaging system and the secondnon-core node is associated with a second plurality of the subscribersserved by the multi-node messaging system, the first non-core node beingcoupled to a first private branch exchange for servicing the firstplurality of the subscribers, the second non-core node being coupled toa second private branch exchange for servicing the second plurality ofthe subscribers, the second plurality of the subscribers being differentfrom the first plurality of the subscribers; and the steps furthercomprise: configuring the first non-core node to receive messages forthe first plurality of the subscribers through the first private branchexchange, thereby obtaining a first plurality of received messages,posting the first plurality of received messages on the first non-corenode without automatically posting the first plurality of messages onthe core node, so that the first plurality of messages is notautomatically available from any non-core node of the plurality ofnon-core nodes other than the first non-core node, and posting anymessage of the first plurality of messages on the core node in responseto a request for said any message from any non-core node of theplurality of non-core nodes other than the first non-core node.
 8. Thearticle of manufacture of claim 1, wherein: the multi-node messagingsystem further comprises a groupware server coupled to the core node;and the steps further comprise configuring the groupware server toreceive, send, and store email messages and contact information for thesubscribers served by the multi-node messaging system.
 9. The article ofmanufacture of claim 1, wherein: the first non-core node is associatedwith a first plurality of the subscribers served by the multi-nodemessaging system and the second non-core node is associated with asecond plurality of the subscribers served by the multi-node messagingsystem, the second plurality of the subscribers being different from thefirst plurality of the subscribers; and the steps further compriseconfiguring said first non-core node to provide one or more firstservices to outside callers that call the first plurality of thesubscribers when the core node is not available to the first non-corenode, said second non-core node is configured to provide the one or morefirst services to outside callers that call the second plurality of thesubscribers when the core node is not available to the second non-corenode, each first service of the one or more first services not requiringupdating of the system configuration information, said each firstservice of the one or more first services not requiring updating of thesubscriber information.
 10. The article of manufacture of claim 1,wherein the portion of the subscriber information replicated comprisesinformation sufficient to route a call received by any non-core node ofthe at least two non-core nodes to any subscriber of the subscribersserved by the multi-node messaging system.
 11. A method of operating amulti-node messaging system comprising a core node and a plurality ofnon-core nodes, each non-core node of the plurality of non-core nodesbeing coupled to telephone switching equipment associated with said eachnon-core node, the method comprising: storing subscriber information forsubscribers served by the multi-node messaging system on the core node;replicating a portion of the subscriber information stored on the corenode to said each non-core node; providing through the core nodecentralized administrative and subscriber access to the subscriberinformation and to the system configuration information; and running oneor more telephony user interface applications for processing telephonecalls at said each non-core node, wherein the one or more telephony userinterface applications enable the multi-node messaging system to receivecalls and voice messages from outside callers to the subscribers servedby the multi-node messaging system, so that the outside callers can callextensions of specific subscribers selected by the outside callers, andso that the outside callers can leave voicemail for the specificsubscribers called by the outside callers, and wherein the one or moretelephony user interface applications configure the multi-node messagingsystem to enable the subscribers served by the multi-node messagingsystem to place through the multi-node messaging system external callsdirected outside the multi-node messaging system, and wherein the one ormore telephony user interface applications running on a first non-corenode of the plurality of non-core nodes comprise a voice user interfaceapplication.
 12. The method of claim 11, wherein the step of replicatingthe portion of the subscriber information comprises replicating allsubscriber information of the multi-node messaging system.
 13. Themethod of claim 11, wherein the first non-core node is associated with afirst plurality of the subscribers served by the multi-node messagingsystem and a second non-core node of the plurality of non-core nodes isassociated with a second plurality of the subscribers served by themulti-node messaging system that is different from the first pluralityof the subscribers served by the multi-node messaging system, the stepof replicating the portion of the subscriber information is performed sothat the portion of the subscriber information replicated to the firstnon-core node comprises information about a second subscriber of thesecond plurality of the subscribers, the first non-core node beingcoupled to a first private branch exchange for servicing the firstplurality of the subscribers, the second non-core node being coupled toa second private branch exchange for servicing the second plurality ofthe subscribers.
 14. The method of claim 11, wherein: the first non-corenode is associated with a first plurality of the subscribers served bythe multi-node messaging system; a second non-core node of the pluralityof non-core nodes is associated with a second plurality of thesubscribers of the multi-node messaging system, the second plurality ofthe subscribers being different from the first plurality of thesubscribers; the step of replicating the portion of the subscriberinformation is performed so that the portion of the subscriberinformation replicated to the first non-core node comprises informationabout each subscriber of the second plurality of the subscribers, theportion of the subscriber information replicated to the second non-corenode comprises information about each subscriber of the first pluralityof the subscribers; the first non-core node is coupled to a firstprivate branch exchange for servicing the first plurality of thesubscribers; and the second non-core node being coupled to a secondprivate branch exchange for servicing the second plurality of thesubscribers.
 15. The method of claim 11, wherein: the first non-corenode is associated with a first plurality of the subscribers of themulti-node messaging system; a second non-core node of the plurality ofnon-core nodes is associated with a second plurality of the subscribersof the multi-node messaging system; the first non-core node is coupledto a first circuit switched private branch exchange for servicing thefirst plurality of the subscribers; the second non-core node is coupledto a second circuit switched private branch exchange for servicing thesecond plurality of the subscribers, the second plurality of thesubscribers being different from the first plurality of the subscribers;and the step of replicating the portion of the subscriber informationcomprises replicating to the first non-core node information sufficientto route a call received by the first non-core node through the firstcircuit switched private branch exchange, the call being directed to anytargeted subscriber of the second plurality of the subscribers, to thetargeted subscriber at the second non-core node through the secondcircuit switched private branch exchange.
 16. The method of claim 11,wherein the multi-node messaging system further comprises a groupwareserver coupled to the core node, the method further comprising:operating the groupware server to receive, send, and store emailmessages and contact information for the subscribers served by themulti-node messaging system.
 17. An article of manufacture comprisingnon-transitory machine-readable storage medium with program code storedin the machine-readable medium, the program code being for operating amulti-node messaging system comprising a core node and a plurality ofnon-core nodes, the plurality of non-core nodes comprising a firstnon-core node and a second non-core node, each non-core node of theplurality of non-core nodes being coupled to telephone switchingequipment associated with said each non-core node, wherein the programcode stores computer instructions for performing steps comprising:storing subscriber information for subscribers served by the multi-nodemessaging system on the core node; replicating a portion of thesubscriber information stored on the core node to said each non-corenode; providing through the core node centralized administrative andsubscriber access to the portion of the subscriber information and tosystem configuration information of the multi-node messaging system; andrunning one or more telephony user interface applications for processingtelephone calls at said each non-core node, wherein the one or moretelephony user interface applications enable the multi-node messagingsystem to receive calls and voice messages from outside callers to thesubscribers served by the multi-node messaging system, so that theoutside callers can call extensions of specific subscribers selected bythe outside callers, and so that the outside callers can leave voicemailfor the specific subscribers called by the outside callers, and whereinthe one or more telephony user interface applications configure themulti-node messaging system to enable the subscribers served by themulti-node messaging system to place through the multi-node messagingsystem external calls directed outside the multi-node messaging system,and wherein the one or more telephony user interface applicationsrunning on a first non-core node of the plurality of non-core nodescomprise a voice user interface application.
 18. The article ofmanufacture of claim 17, wherein the step of replicating the portion ofthe subscriber information comprises replicating all subscriberinformation of the multi-node messaging system.
 19. The article ofmanufacture of claim 17, wherein the first non-core node is associatedwith a first plurality of the subscribers served by the multi-nodemessaging system and a second non-core node of the plurality of non-corenodes is associated with a second plurality of the subscribers served bythe multi-node messaging system that is different from the firstplurality of the subscribers served by the multi-node messaging system,the step of replicating the portion of the subscriber information isperformed so that the portion of the subscriber information replicatedto the first non-core node comprises information about a secondsubscriber of the second plurality of the subscribers, the firstnon-core node being coupled to a first private branch exchange forservicing the first plurality of the subscribers, the second non-corenode being coupled to a second private branch exchange for servicing thesecond plurality of the subscribers.
 20. The article of manufacture ofclaim 17, wherein: the first non-core node is associated with a firstplurality of the subscribers served by the multi-node messaging system;a second non-core node of the plurality of non-core nodes is associatedwith a second plurality of the subscribers of the multi-node messagingsystem, the second plurality of the subscribers being different from thefirst plurality of the subscribers; the step of replicating the portionof the subscriber information is performed so that the portion of thesubscriber information replicated to the first non-core node comprisesinformation about each subscriber of the second plurality of thesubscribers, the portion of the subscriber information replicated to thesecond non-core node comprises information about each subscriber of thefirst plurality of the subscribers; the first non-core node is coupledto a first private branch exchange for servicing the first plurality ofthe subscribers; and the second non-core node being coupled to a secondprivate branch exchange for servicing the second plurality of thesubscribers.